Sir Norman Bettison has resigned as chief constable of West Yorkshire Police, saying an inquiry into his role after the Hillsborough tragedy was "a distraction" to the force.

At the time of the disaster he was a South Yorkshire Police inspector who attended the match as a spectator and later took part in an internal inquiry.

Sir Norman has denied claims he helped "concoct" a false version of events.

He had been due to retire in March but had faced calls for him to go early.

The Independent Police Complaints Commission (IPCC), which is undertaking two investigations into Sir Norman, issued a statement saying: "Retirement or resignation does not prevent criminal prosecution should the investigation identify criminal offences, including misconduct in a public office."

Margaret Aspinall, chairwoman of the Hillsborough Families Support Group, said: "I'm absolutely delighted he's gone but as far as I am concerned he should have been sacked.

"I would now like to know what payments and pension he's going to get.

"Any financial benefits should be frozen until the outcome of the investigation into the cover-up."

West Yorkshire Police Authority said media attention and the investigations by the IPCC were "proving to be a huge distraction for the force".

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Media captionLiverpool Mayor Joe Anderson: "Most people will find it offensive that he will continue to receive a huge pension whilst this investigation continues"

Statements altered

Sir Norman has been referred to the IPCC over allegations he provided misleading information after the disaster, in which 96 Liverpool fans died.

Last month, a report by the Independent Hillsborough Panel revealed 164 police statements by South Yorkshire Police were altered - 116 of them to remove or change negative comments about the policing of the FA Cup semi-final between Liverpool and Nottingham Forest at the Sheffield stadium.

It revealed a cover-up took place to shift the blame on to the victims, and that 41 of the 96 who died could have potentially been saved if they had received treatment earlier.

In a statement last month, Sir Norman said: "Fans' behaviour, to the extent that it was relevant at all, made the job of the police, in the crush outside Leppings Lane turnstiles, harder than it needed to be."

He apologised a day later saying Liverpool fans were "in no way to blame" for the disaster and that he was sorry if he had "caused any further upset".

Sir Norman's resignation comes after candidates bidding to become West Yorkshire's police and crime commissioner called for him to stand down now rather than retire in March as planned.

In a statement, he said: "The police authority, and some of the candidates in the forthcoming PCC elections, have made it clear that they wish me to go sooner.

'Deep concerns'

"I do so, not because of any allegations about the past, but because I share the view that this has become a distraction to policing in West Yorkshire now and in the future."

The police authority said Deputy Chief Constable John Parkinson would take up the role of acting chief constable.

A Home Office spokesperson said Sir Norman's resignation was "a matter for the police authority".

Policing minister Damian Green said it was important that the West Yorkshire force was able to get on with the job of policing.

"If the inevitable deep concerns surrounding all of this - which, clearly, would be very, very understandable - were getting in the way of doing that job, then it is clearly sensible to allow West Yorkshire Police to get on with their important work."